Lawyers for Auction Alliance filed papers in the Western Cape High Court yesterday to challenge the warrant used by an anti-corruption task team which raided the company's 13 offices around the country on Tuesday.

Members of the Hawks, the SAPS, the Special Investigating Unit, the Treasury and the National Prosecuting Authority conducted the simultaneous raids.

The raids formed part of a continuing investigation by the Hawks into allegations of kickbacks paid by the company to senior bank staff, liquidators and attorneys, and bogus bidding practices.

Yesterday, Dale Smiedt, one of the lawyers for Auction Alliance, said: "The State has provided us with certain documents which on a prima face basis have been issued unlawfully and unconstitutionally and in flagrant violation of our client's rights. In the circumstances, we are considering the various remedies available..."

National police spokesman Captain Dennis Adriao would not give details of the items confiscated at the offices.

The raids come nearly a month after the National Consumer Tribunal set aside an order which found Auction Alliance guilty of contravening the Consumer Protection Act during the controversial Quoin Rock Wine Estate auction in December.

The tribunal overturned a decision made by the National Consumer Commission (NCC) which found the auction house guilty of conducting a "mock" auction by using a ghost bidder to drive up the sale price.

Billionaire businesswoman Wendy Appelbaum, the winning bidder, disputed the process, saying she had been the only genuine bidder and had bid against herself.

The dispute led to the inner dealings of the company being exposed, which included allegations of kickbacks and the use of ghost bidders to drive up prices.

When the order was set aside, another lawyer for the company, Alan Smiedt, said the company was "exonerated" on the Quoin Rock matter.

The National Consumer Tribunal has still not given reasons for setting aside the NCC ruling, but has said it would do so "in due course".

Meanwhile, the NCC says it is investigating five other complaints against Auction Alliance.

Earlier this year, Auction Alliance founder and former chief executive Rael Levitt stepped down and also resigned as a SA Institute of Auctioneers board member.

In June, Auction Alliance successfully challenged another warrant when the Western Cape High Court turned down an application for a search-and-seizure warrant by the Estate Agencies Affairs Board.